Virtual planning and CAD/CAM-assisted distraction for maxillary hypoplasia in cleft lip and palate patients: Accuracy evaluation and clinical outcome

Comparison of Maxillary Distraction Osteogenesis and Conventional Orthognathic Osteotomy: A Systematic Review

Maxillary hypoplasia, affecting 0.3% of the US population and nearly 25% of patients with cleft lip and/or palate (CLP), often results in Class III malocclusion with significant functional and esthetic challenges. Treatment options include LeFort I distraction osteogenesis (DO) and conventional osteotomy (CO), but reported outcomes vary widely. A systematic review of PubMed, Embase, Scopus, and CINAHL identified 17 studies (6 randomized controlled trials, 11 retrospective cohort studies) from 5076 screened. Outcomes assessed included skeletal relapse, speech changes, velopharyngeal insufficiency (VPI), soft tissue adaptations, and complications. Study quality was evaluated using the Newcastle-Ottawa scale and Cochrane risk-of-bias tool. Findings showed no significant differences in skeletal relapse between DO and CO. Speech and VPI outcomes were comparable, with deterioration in 10% to 45% of DO patients and 22.2% to 81.8% of CO patients. DO provide superior soft tissue improvements, particularly in nasal and lip landmarks. Complication rates ranged from 5% to 20% for DO and 21% to 22.2% for CO. Overall, evidence comparing DO and CO remains limited and inconsistent, preventing definitive conclusions on skeletal stability, speech outcomes, VPI risk, and complications. While DO may offer better soft tissue outcomes, it shares high complication rates and patient dissatisfaction. Further research is essential.

Three-dimensional anatomical analysis of the optic nerve canal with virtual model based on CBCT

The optic nerve canal (ONC) is a fine skeletal structure that contains the optic nerve. However, it has not been thoroughly examined. This necessitates establishing a baseline knowledge of the geometrical and volumetric parameters of the ONC. The data of twenty patients who received a cone beam computed tomography examination were prepared using a voxel-based segmentation. The measurement was performed separately by two examiners on virtual skull models in stereolithography format in Geomagic Wrap®. The results showed that the volume of the ONC varied between 92.48 mm3 and 162.7 mm3 (M = 123.46 mm3, SD = 26.61 mm3). Sex-specific statistically significant differences in volume were detected only for the right side. The angle of the ONC to the skull base was independent of the diameter of the canal. Both the intrarater and interrater comparisons of the measurements showed high values of reproducibility of the results. This study showed that a virtual anatomical model provides a feasible and reliable method to investigate the ONC. The examination technique could have a wider range of application in anthropology and application in clinical medicine. Advances in the automation of radiological diagnostics and the digital analysis of X-ray images could help to reduce examination times.

Efficacy of modified anterior maxillary segmental distraction osteogenesis based on 3D visualisation for the treatment of maxillary hypoplasia among adolescents with cleft lip and palate

BACKGROUND

This study evaluates a three-dimensional (3D) visualisation design combined with customized surgical guides to assist anterior maxillary segmental distraction osteogenesis (AMSDO) in correcting maxillary hypoplasia in adolescents with cleft lip and palate (CLP), focusing on treatment outcomes, satisfaction and the validity of 3D planning.

METHODS

This retrospective cohort study was conducted at a single hospital in China. Between January 2020 and December 2023, 12 adolescents with CLP with maxillary hypoplasia were included. An advanced 3D simulation was used to convey the treatment strategy to the patients and their families. A customized surgical guide and distraction osteogenesis device were designed. Cephalometric analysis evaluated AMSDO changes and long-term stability. Patient satisfaction was assessed. The Chinese version of the Child Oral Health Impact Profile was used to evaluate the children's oral health-related quality of life before and after treatment. The postoperative outcomes were compared with the planned outcomes by superimposing the actual postoperative data onto the simulated soft tissue models and calculating the linear and angular differences between them.

RESULTS

One patient experienced postoperative gingivitis, yielding an 8.33% complication rate. Most patients (83.33%) were highly satisfied with the target position, with the rest content. Cephalometric analysis showed significant improvements in various indices post-traction. Quality-of-life scores significantly improved post-treatment. The discrepancies in facial soft tissue between the simulated and actual results were within clinically satisfactory ranges.

CONCLUSIONS

Digitally designed surgical guides effectively treat maxillary hypoplasia in adolescents with CLP, ensuring stability, reducing complications, reducing dependency on operator experience, and enhancing satisfaction and health outcomes. Although the simulated results were clinically acceptable, it is important to inform patients of potential variations in the predicted soft tissue.

Automatic orbital segmentation using deep learning-based 2D U-net and accuracy evaluation: A retrospective study

The purpose of this study was to verify whether the accuracy of automatic segmentation (AS) of computed tomography (CT) images of fractured orbits using deep learning (DL) is sufficient for clinical application. In the surgery of orbital fractures, many methods have been reported to create a 3D anatomical model for use as a reference. However, because the orbit bone is thin and complex, creating a segmentation model for 3D printing is complicated and time-consuming. Here, the training of DL was performed using U-Net as the DL model, and the AS output was validated with Dice coefficients and average symmetry surface distance (ASSD). In addition, the AS output was 3D printed and evaluated for accuracy by four surgeons, each with over 15 years of clinical experience. One hundred twenty-five CT images were prepared, and manual orbital segmentation was performed in all cases. Ten orbital fracture cases were randomly selected as validation data, and the remaining 115 were set as training data. AS was successful in all cases, with good accuracy: Dice, 0.860 ± 0.033 (mean ± SD); ASSD, 0.713 ± 0.212 mm. In evaluating AS accuracy, the expert surgeons generally considered that it could be used for surgical support without further modification. The orbital AS algorithm developed using DL in this study is extremely accurate and can create 3D models rapidly at low cost, potentially enabling safer and more accurate surgeries.

Augmented reality hologram combined with pre-bent distractor enhanced the accuracy of distraction vector transfer in maxillary distraction osteogenesis, a study based on 3D printed phantoms

BACKGROUND

Vector control is a significant concern in maxillary distraction osteogenesis (DO). Distraction vector planning on the patient's 3D-printed skull phantom is more intuitive for surgeons and cost-efficient than virtual surgical planning. However, the accuracy of transferring the planned vector to intraoperative (vector transfer) according to the shape of the pre-bent footplate alone is relatively limited. The application of augmented reality (AR) in surgical navigation has been studied for years. However, few studies have focused on its role in maxillary DO vector transfer. This study aimed to evaluate the accuracy of AR surgical navigation combined with the pre-bent distractor in vector transfer by comparing it with the pre-bent distractor alone.

METHODS

Ten patients with maxillary hypoplasia were enrolled with consent, and three identical 3D-printed skull phantoms were manufactured based on per patient's corresponding pre-operative CT data. Among these, one phantom was for pre-operative planning (n = 10), while and the other two were for the AR+Pre-bending group (n = 10) and the Pre-bending group (n = 10) for the experimental surgery, respectively. In the Pre-bending group, the distraction vector was solely determined by matching the shape of footplates and maxillary surface. In the AR+Pre-bending group, the distractors were first confirmed to have no deformation. Then AR surgical navigation was applied to check and adjust the vector in addition to the steps as in the Pre-bending Group.

RESULTS

For the angular deviation of the distraction vector, the AR+Pre-bending group was significantly smaller than the Pre-bending group in spatial (p < 0.001), x-y plane (p = 0.002), and y-z plane (p < 0.001), and there were no significant differences in the x-z plane (p = 0.221). The AR+Pre-bending group was more accurate in deviations of the Euclidean distance (p = 0.004) and the y-axis (p = 0.011). In addition, the AR+Pre-bending group was more accurate for the distraction result.

CONCLUSIONS

In this study based on 3D printed skull phantoms, the AR surgical navigation combined with the pre-bent distractor enhanced the accuracy of vector transfer in maxillary DO, compared with the pre-bending technique alone.

A bibliometric analysis of research on craniomaxillofacial distraction osteogenesis from 2000 to 2021

Objective

This study collected and summarized publications related to craniomaxillofacial distraction osteogenesis(DO) from 2000 to 2021, investigated trends in related research, and compared publications from different countries, institutions and journals. The aim is showcasing hotspots and frontiers in the field and providing a reference for future research.

Background

Craniomaxillofacial DO serves to treat different types of craniomaxillofacial dysplasia and bone defects and deformities. DO can significantly reduce surgical trauma, complications, and recurrence rate compared to conventional surgery. However, there is a lack of bibliometric analyses regarding Craniomaxillofacial DO.

Methods

CiteSpace and VOSviewer were used to analyze and visualize 3,141 articles and reviews searching through the Web of Science Core Collection(WOSCC) to obtain publications on craniomaxillofacial DO from 1 January 2000 to 31 December 2021.

Results

In the last 21 years, there has been a significant increase in the number of publications. The United States, the People's Republic of China, and Italy produce the vast majority of publications. University of Milan and University of Bologna are the most influential in this field. McCarthy JG is the most influential author. Obstructive sleep apnea, TMJ ankylosis and cleft lip and palate are potential research direction in this field.

Conclusion

Future research should focus on the precise indications and optimal timing of craniomaxillofacial DO and the evaluation of the long-term outcomes of various modified procedures. This study provides a relatively objective reference for related researchers, medical practitioners, and global health systems.